632.782:632.92:632.939.1 :634.l/.2 C. J. A. BAREL STUDIES ON DISPERSAL OF ADOXOPHYES ORANA F.v.R. IN RELATION TO THE POPULATION STERILIZATION TECHNIQUE PROEFSCHRIFT TER VERKRIJGING VAN DE GRAAD VAN DOCTOR IN DE LANDBOUWWETENSCHAPPEN, OP GEZAG VAN DE RECTOR MAGNIFICUS, PROF. DR. IR. H. A. LENIGER, HOOGLERAAR IN DE TECHNOLOGIE, IN HET OPENBAAR TE VERDEDIGEN OP VRIJDAG 22 JUNI 1973 DES NAMIDDAGS TE VIER UUR IN DE AULA VAN DE LANDBOUWHOGESCHOOL TE WAGENINGEN H. VEENMAN & ZONEN - WAGENINGEN - 1973 Dit proefschrift met stellingen van CORNELIS JOHANNES ADRIANUS BAREL landbouwkundig ingenieur, geboren te Klundert op 3jun i 1944, is goedgekeurd door de promotor, Dr. J. de Wilde, hoogleraar in het dierkundig deel van de Plantenziektenkunde. De Rector Magnificus van de Landbouwhogeschool, H. A. LEMGER Wageningen, 19apri l197 3 This thesis is also published as Mededelingen Landbouwhogeschool Wageningen 73-7(1973 ) (Communications Agricultural University Wageningen, The Netherlands) STELLINGEN r De snelle verbreiding van de vruchtbladroller binnen Nederland en Belgie kan niet alleen worden toegeschreven aan het vliegen van de imagines. Dit proefschrift II Ethologisch gezien ishe t zich laten zakken aan spinseldraden van de rupsen van de vruchtbladroller een vluchtgedrag. In de loop van de evolutie heeft dit gedrag echter ook betekenis gekregen voor de verspreiding vand e rupsen over korte afstanden. Dit proefschrift III De evenredigheid tussen hetaanta l gevangen dieren inee nsexva l end e groot- te van de populatiedichtheid vermindert naarmate de laatste toeneemt. IV Het onderzoek naar de mogelijkheden van het kweken en uitzetten van pre- datoren en parasieten, die resistent zijn tegen bepaalde bestrijdingsmiddelen, dient te worden gestimuleerd. CROFT, B. A., BARNES, M. ML, 1971. J. econ. Ent., 64:845-850. HOYT, S. C, 1969. J. econ. Ent., 62:74-86. V Toepassing van fungiciden uit de benzimidazool-groep in granen maakt vruchtwisseling noodzakelijk. VI Bij het stellen van criteria ten aanzien van schadelijke nevenwerkingen van bestrijdingsmiddelen in het milieu dient men, bij stoffen die in de bouwvoor blijven, rekening te houden metd e bestemming van dit deel van het milieu. VII Gezien deverdelin g van hetaanta l aardappelbladeren mettopro l symptomen binnen eenaangetast e plek, moet luchtverontreiniging als mogelijke eersteoor - zaak uitgesloten worden geacht. VIII De hypothese dat een virus betrokken zou zijn bij de teruggang van Gaeu- mannomyces graminis, onder omstandigheden van eenzijdige graanteelt, moet verworpen worden. LAPIERRE, H., et al., 1970.C . R. Acad. Sc. Paris, 271 serie D: 1833-1836. GERLAGH, ML,1968 . Diss. Wageningen. IX De disjuncte verspreiding vanpersistent e virussen inee nvel d kan niet alleen vvorden toegeschreven aan de activiteit van gevleugelde bladluizen. FRANCOIS, E.,e t al., 1968. Isotopes andradiatio n in Entomology. Proceedings series, IAEA Vienna: 53-68. X Toepassing vand e steriele-mannetjestechniek bij de bestrijding van fytofage insektcn zal slechts dan kunnen leiden tot een verminderd gebruik van insekti- ciden, indien in het areaal vand eplaa g geen verwante soorten voorkomen met vergclijkbare ecologische niches. Proefschrift C. J. A. BVREL. 22 juni Il>73. Aan mijn Ouclers CONTENTS 1. INTRODUCTION 1 2. GEOGRAPHICAL DISTRIBUTION, LIFE HISTORY AND HOSTPLANT RANGE 4 3. MATERIALS AND GENERAL METHODS 14 3.1. Moths 14 3.2. Diet 14 3.3. Marking 14 3.4. Light traps 15 3.5. Sex traps 15 4. MODES OF DISPERSAL 16 4.1. General 16 4.2. Adult dispersal 17 4.2.1. Light traps 17 4.2.1.1. Materials and methods 17 4.2.1.2. Experiment 1 18 4.2.1.3. Experiment 2 20 4.2.1.4. Experiment 3 23 4.2.1.5. Discusssion 34 4.2.2. Sex traps 44 4.2.2.1. Maximum distance a male can fly 44 4.2.2.2. Release-recapture experiment in an orchard 45 4.2.2.3. Sex traps used in recapture experiments, outside orchards 47 4.2.2.3.1. Observations on moths crossing an open field 48 4.2.2.3.2. Observations on moths leaving a wood, using only sex traps 50 4.2.2.3.3. Observations on moths moving along hedgerows 53 4.2.2.4. Discussion 61 4.3. Aerial transport of larvae 62 4.3.1. General 62 4.3.2. Losses of larvae, other than by means of air currents 63 4.3.3. Losses of larvae, including by means of air currents 63 4.3.4. Release-recapture experiments with newly-hatched larvae 65 4.3.5. Geotaxis and phototaxis 66 4.3.6. Behaviour of newly-hatched larvae in a wind tunnel 69 4.3.7. Discussion 69 4.4. Occurrence of the species in a newly reclaimed area 69 5. VARIABILITY OF RESPONSE TOWARDS DIFFERENT HOSTPLANTS . 72 5.1. General 72 5.2. Search for oviposition preference 73 5.3. Search for differences in rate of development and growth rate of larvae on different plants of the hostplant range 75 5.4. Crossing experiments 77 5.5. Discussion 78 6. POPULATION DENSITIES OUTSIDE ORCHARDS 79 6.1. General 79 6.2. Materials and methods 79 6.3. Estimates during the first flight 80 6.4. Estimates during the second flight 81 6.5. Discussion 84 7. LABORATORY EXPERIMENTS ON FLIGHT ACTIVITY 86 7.1. Changes of these xrati oi nth enumber s caught inrelatio n to the distance between release point and light trap 86 7.2. Distribution of moths in the corridor, between the light trap and the release point 87 7.3. Diurnal periods of flight activity, differences between males and females 88 8. DISCUSSION AND CONCLUSION 95 9. SUMMARY . 99 10. ACKNOWLEDGEMENTS 101 11. SAMENVATTING 102 12. REFERENCES 104 1. INTRODUCTION In the Netherlands, Adoxophyes oranai sa serious pest in pome fruit growing. Growers, on an average, apply three insecticide sprayings per year against this tortricid. An organic phosphorous compound is mostly used. These compounds are highly toxic, not only to arthropods, but also to fishes and mammals. Although the benefits of pesticides to man cannot be denied, the disadvan­ tages of an unlimited use become more and more apparent. On one hand, there is the justified concern about pollution of the environment, on the other hand there isth e build up of resistance and the development of new pests as a result of the use of pesticides. For these reasons alternative modes of plant protection are being sought. In the Netherlands, within the frame of 'Werkgroep gei'ntegreerde bestrijding van plagen T.N.O.' (Integrated control working party T.N.O.), a group of research workers is studying the possibilities for integrated control in orchards. In Dutch pome fruit growing two key-pests can be distinguished, Panonychus ulmi (red spider mite) and A. orana (summer fruit tortricid). P. ulmi is the most serious pest, and moreover it regularly develops resistance to acaricides, whilst inA. oranaresistanc e has never been observed. Evidence has been found, which makes it likely that P. ulmi can be controlled by predators (VAN DE VRIE 1972). However these predators can never have a chance when the spraying of non selective insecticides against other pests is continued. Hence alternative con­ trol measures for A. orana were sought, the latter being the second important pest. A meridic diet for A. oranaha d already been developed (ANKERSMIT 1968), which would facilitate mass-rearing. This led to the idea of controlling the insect by means of releasing sterile adults. POPULATION STERILIZATION TECHNIQUE For the application of the population sterilization technique, at least four requirements have to be fullfilled. a. Mass-rearing must be possible, as large numbers are needed for the releases. b. Sterilization must be possible, without detrimental side-effects on longevity and behaviour. c. Population density must be low, as the numbers to be released are multiple of the numbers present. d. Dispersal must be restricted, as the chances for reinfestation of a once cleared area depend on the abilities for dispersal. The greater the dispersal the larger the area which has to be treated. The term dispersal covers any movement from one habitat to another, in contrast to movements within the habitat. This more or less corresponds with the distinction between migratory movements and trivial movements made by KENNEDY and SOUTHWOOD (SOUTHWOOD 1962). This distinction stresses differ- Meded. Landbouwhogeschool Wageningen 73-7 (1973) ' 1 ences in motivation. For our purpose we are more interested in the resulting activity. The first two requirements for application of the population sterilization technique have been fullfilled. Mass-rearing on an experimental scale is possible and sterilization does not cause detrimental side-effects (SNIEDER et al. 1973) Population density however, does not meet the requirements. In 1968, at the first flight, DE JONG estimated the population density in one orchard to be about 1500moth s per ha and in another, at 3600moth spe rh a (ANKERSMITan d DE JONG 1970). During the second flight the population density is usually larger. This is a very high density as compared to the classic example of the successful erad­ ication of the screw-worm, Cochliomiya hominivorax, which had an average density of about 70 per square kilometer (BUSHLAND 1960). Moreover A. orana does not only occur in orchards. The species is poly- phagous and isfoun d on nearly alldeciduou stree san d shrubs and alsoo n several herbaceous plants (JANSSEN 1958). With regard to dispersal, data about captures in light traps outside orchards suggested that this was not very important (DE FLUITER et al. 1963). This could be related to the hovering type of flight of the adults. ALTERNATIVE FOR ERADICATION In view of the abundance and the wide and continuous area of dispersal, the idea of eradication had to be abandoned.